Method and system for decoding low density parity check (LDPC) codes
AssigneeHughes Electronics Corporation
InventorsMustafa Eroz, Feng-Wen Sun, Lin-Nan Lee
Life of this patent
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Abstract
An approach is provided for transmitting messages using low density parity check (LDPC) codes. Input messages are encoded according to a structured parity check matrix that imposes restrictions on a sub-matrix of the parity check matrix to generate LDPC codes. The LDPC codes are transmitted over a radio communication system (e.g., satellite network), wherein a receiver communicating over the radio communication system is configured to iteratively decode the received LDPC codes according to a signal constellation associated with the LDPC codes. The receiver is configured to iteratively regenerating signal constellation bit metrics after one or more decoding iterations.
Claims24
A method for decoding low density parity check (LDPC) codes, the method comprising:
- receiving a priori probability information based on distance vector information relating to
- distances between received noisy symbol points and symbol points of a signal
- constellation associated with the LDPC codes;
- transmitting a posteriori probability information based on the a priori probability information;
- determining whether parity check equations associated with the LDPC codes are satisfied according to the a priori probability and the a posteriori probability information;
- selectively regenerating the signal constellation bit metrics based on the determining step;
- and
- outputting decoded messages based on the regenerated signal constellation bit metrics.
A system for decoding low density parity check (LDPC) codes, the system comprising:
- means for receiving a priori probability information based on distance vector information relating to distances between received noisy symbol points and symbol points of a signal constellation associated with the LDPC codes;
- means for transmitting a posteriori probability information based on the a priori probability information;
- means for determining whether parity check equations associated with the LDPC codes are satisfied according to the a priori probability and the a posteriori probability information;
- means for selectively regenerating the signal constellation bit metrics based on the determination;
- and
- means for outputting decoded messages based on the regenerated signal constellation bit metrics.
A receiver for decoding low density parity check (LDPC) codes, the receiver comprising:
- a bit metric generator configured to generate a priori probability information based on distance vector information relating to distances between received noisy symbol points and symbol points of a signal constellation associated with the LDPC codes;
- and
- a decoder configured to output a posteriori probability information based on the a priori probability information received from the bit metric generator, wherein the decoder is further configured to determine whether parity check equations associated with the LDPC codes are satisfied according to the a priori probability and the a posteriori probability information, the decoder outputting decoded messages based on a regenerated signal constellation bit metrics if the parity check equations are not satisfied.
A method for transmitting messages using low density parity check (LDPC) codes, the method comprising:
- encoding input messages according to a structured parity check matrix that imposes restrictions on a sub-matrix of the parity check matrix to generate LDPC codes;
- and
- transmitting the LDPC codes over a radio communication system, wherein a receiver communicating over the radio communication system is configured to iteratively decode the received LDPC codes according to a signal constellation associated with the LDPC codes, the receiver configured to iteratively regenerating signal constellation bit metrics after one or more decoding iterations.
Dependencies are inferred from the claim text.